/*
 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package org.eclipse.imagen.tilecodec;

import java.io.InputStream;
import org.eclipse.imagen.NegotiableCapability;

/**
 * A factory for creating <code>TileDecoder</code>s.
 *
 * <p>This class stipulates that the capabilities of the <code>TileDecoder</code> be specified by implementing the
 * <code>getDecodingCapability()</code> method.
 *
 * @see org.eclipse.imagen.NegotiableCapability
 * @since JAI 1.1
 */
public interface TileDecoderFactory {

    /**
     * Creates a <code>TileDecoder</code> capable of decoding the encoded data from the given <code>InputStream</code>
     * using the specified <code>TileCodecParameterList</code> containing the decoding parameters to be used.
     *
     * <p>This method can return null if the <code>TileDecoder</code> is not capable of producing output for the given
     * set of parameters. For example, if a <code>TileDecoder</code> is only capable of dealing with a jpeg quality
     * factor of 0.5, and the associated <code>TileCodecParameterList</code> specifies a quality factor of 0.75, null
     * should be returned.
     *
     * <p>It is recommended that the data in the supplied <code>InputStream</code> not be used as a factor in
     * determining whether this <code>InputStream</code> can be successfully decoded, unless the supplied <code>
     * InputStream</code> is known to be rewindable (i.e. its <code>markSupported()</code> method returns true or it has
     * additional functionality that allows backward seeking). It is required that the <code>InputStream</code> contain
     * the same data on returning from this method as before this method was called. In other words, the <code>
     * InputStream</code> should only be used as a discriminator if it can be rewound to its starting position before
     * returning from this method. Note that wrapping the incoming <code>InputStream</code> in a <code>
     * PushbackInputStream</code> and then rewinding the <code>PushbackInputStream</code> before returning does not
     * rewind the wrapped <code>InputStream</code>.
     *
     * <p>If the supplied <code>TileCodecParameterList</code> is null, a default <code>TileCodecParameterList</code>
     * from the <code>TileCodecDescriptor</code> will be used to create the decoder.
     *
     * <p>Exceptions thrown by the <code>TileDecoder</code> will be caught by this method and will not be propagated.
     *
     * @param input The <code>InputStream</code> containing the encoded data to decode.
     * @param param The parameters to be be used in the decoding process.
     * @throws IllegalArgumentException if input is null.
     */
    TileDecoder createDecoder(InputStream input, TileCodecParameterList param);

    /**
     * Returns the capabilities of this <code>TileDecoder</code> as a <code>NegotiableCapability</code>.
     *
     * @see org.eclipse.imagen.NegotiableCapability
     */
    NegotiableCapability getDecodeCapability();
}
